The present invention relates generally to end effectors and attachments for robotic apparatuses. More particularly, the present invention relates to an attachment for a robotic apparatus which is operable for repositioning a closure member which has been movably mounted to a workpiece.
Backround Art
Robotic apparatuses are commonly employed in modern high-volume fabrication operations to perform repetitive tasks which would otherwise be tedious, fatiguing and/or difficult to perform manually in a cycle time of relatively short duration. One such task concerns the painting of a workpiece, such as an automotive vehicle, where high volume airless sprayers are frequently employed to coat the vehicle body with a film of liquid paint. The robust nature of a robotic apparatus permits the paint to be applied at volumes and pressures which are relatively high; these relatively high volumes and pressures typically cannot be employed when manually applying paint as the reaction force exerted onto the paint technician would render the spraying equipment difficult to control and fatiguing to operate.
Despite the advantages of robotic apparatuses, several drawbacks have been noted, particularly where a robotic apparatus is employed to perform a rather delicate operation wherein the workpiece is easily scratched or damaged if a portion of the robotic apparatus is slid along the workpiece. One common example concerns pivoting a hinged member of a workpiece. This situation is frequently encountered when repositioning the vehicle doors of an automotive vehicle as a vehicle is processed in a fabrication plant to permit the doorjamb of the vehicle body to be painted or to permit components such as seats to be installed to the vehicle.
The known attachment devices, including end effectors, typically lack the degree of freedom that is necessary to prevent the robotic apparatus from sliding relative to the hinged member of the workpiece, causing the attachment device or end effector to scratch and/or mar the finish of the workpiece. Accordingly, there remains a need in the art for an attachment device for a robotic apparatus which permits the arm assembly of a robotic apparatus to be employed to reposition the hinged member of a workpiece without scratching, marring or otherwise degrading the finish of the workpiece.
It is a general object of the present invention to provide a positioning device for a robotic apparatus which permits an arm assembly of the robotic apparatus to reposition a closure member which is movably mounted to a workpiece.
It is another object of the present invention to provide a positioning device which employs a flange assembly having a rotatable flange structure which permits a closure member of a workpiece to be movably repositioned without sliding the flange assembly along the closure member.
In one preferred form, the present invention provides a positioning device for positioning a movably mounted portion of a workpiece. The positioning device includes an attachment structure, a rod, a flange assembly and an engagement mechanism. The attachment structure includes a rod aperture and is coupled to a robotic apparatus. The rod is disposed within the rod aperture and is slidably positionable therein. The flange assembly is coupled to a distal end of the rod and includes a flange structure. The flange structure is rotatable relative to the rod and engages the movably mounted portion of the workpiece. The engagement mechanism is coupled to the attachment structure and is operable for moving the rod in an axial direction within the rod aperture. The engagement mechanism applies an axially directed force to the flange assembly to maintain the flange structure in a stationary position relative to the pivotably mounted portion of the workpiece when the movably mounted portion of the workpiece is moved relative to a remaining portion of the workpiece.